famous scientist who contributed to structure of atom!

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John Dalton By: Mohammed Fadhil Kabeer

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Page 1: Famous scientist who contributed to structure of atom!

John Dalton

By: Mohammed Fadhil Kabeer

Page 2: Famous scientist who contributed to structure of atom!

Background Lived from September 6, 1766

– July 27, 1844

English chemist, Meteorologist, And Physicist.

Born into a Quaker family at Eaglesfield in Cumberland, England.

At age of 15 helped his older brother run a Quaker school in nearby Kendal

Dalton was heavily influenced in early life by Elihu Robinson, who was a meteorologist and instrument maker. This got him started into mathematics and meteorology.

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Contributions

Color blindness- He lead a lot of research in the area of color blindness and because of it the common term for color blindness became “Daltonism” in his honor.

He was one of the first to even formally publish about color blindness at the time.

He followed this essays with many on different topics such as reflection and refraction of light.

(Fun Fact): He Himself was color blind

Daltons law- The law of partial pressures.

Statue of Dalton in Manchester Town Hall

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Contributions (cont.)

Daltons Atomic Theory

This theory had five main points

The atoms of a given element are different from those of any other element; the atoms of different elements can be distinguished from one another by their respective relative atomic weights.

All atoms of a given element are identical.

Atoms of one element can combine with atoms of other elements to form chemical compounds; a given compound always has the same relative numbers of types of atoms.

Atoms cannot be created, divided into smaller particles, nor destroyed in the chemical process; a chemical reaction simply changes the way atoms are grouped together

Elements are made of tiny particles called atoms.

Page 5: Famous scientist who contributed to structure of atom!

Justice

He didn’t actually find or figure out color blindness he just built off other peoples work and did research but it still became commonly known as “Daltonism”

He also didn’t come up with the base of most of his theories for example “Daltons law” (law of Partial Pressures) was really based off Charles’s law (Gay-Lussac’s law)

Page 6: Famous scientist who contributed to structure of atom!

Michael Faraday

By: Mohammed Fadhil Kabeer

Page 7: Famous scientist who contributed to structure of atom!

Early Childhoo

d Faraday was born in

1791

Grew up near London in slums known as Newington Butts

His father was a blacksmith

Family was poor

Had very little education

Physically weak

Page 8: Famous scientist who contributed to structure of atom!

Life as A book Binder

Physical handicap led him to bookbinding

Apprentice to master Georges Reibau

Reading and bookbinding

Encyclopedia Brittannica and Conversations on Chemistry

Successor Of Sir Humphry Davy

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Discoveries

Electromagnetic Induction

Electrical field and electrical currents

How could he continuously create this phenomena?

Page 10: Famous scientist who contributed to structure of atom!

Importance Of His Discoveries

The electric generator allowed for electric energy to be produced without the consumption of chemical energy

Using turbines to produce electricity

Using water, steam, coal, oil, wind to power turbines

Electricity on a larger scale

Page 11: Famous scientist who contributed to structure of atom!

William Crookes

By: Mohammed Fadhil Kabeer

Page 12: Famous scientist who contributed to structure of atom!

J.J. Thomson

By: Mohammed Fadhil Kabeer

Page 13: Famous scientist who contributed to structure of atom!

Introduction

Sir Joseph John "J. J." Thomson (18 December 1856 – 30 August 1940) was a British physicist and Nobel laureate.

He is credited with discovering electrons and isotopes, and inventing the mass spectrometer.

Thomson was awarded the 1906 Nobel Prize in Physics for the discovery of the electron and for his work on the conduction of electricity in gases.

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What Did He Prove?

Thomson, in 1897, was the first to suggest that the fundamental unit was over 1000 times smaller than an atom, suggesting the sub-atomic particles now known as electrons. Thomson discovered this through his explorations on the properties of cathode rays.

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Picture of Cathode Ray Experiment

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His Other Works

In 1905 Thomson discovered the natural radioactivity of potassium.

In 1906 Thomson demonstrated that hydrogen had only a single electron per atom. Previous theories allowed various numbers of electrons.

Page 17: Famous scientist who contributed to structure of atom!

Awards

Royal Medal (1894)

Hughes Medal (1902)

Nobel Prize for Physics (1906)

Elliott Cresson Medal (1910)

Copley Medal (1914)

Franklin Medal (1922)

Page 18: Famous scientist who contributed to structure of atom!

Eugen Goldstein

By: Mohammed Fadhil Kabeer

Page 19: Famous scientist who contributed to structure of atom!

Introduction

Eugen Goldstein (September 5, 1850 – December 25, 1930) was a German physicist. He was an early investigator of discharge tubes, the discoverer of anode rays, and is sometimes credited with the discovery of the proton.

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James Chadviek

By: Mohammed Fadhil Kabeer

Page 22: Famous scientist who contributed to structure of atom!

Background

Born: October 20 1891

Died: July 24 1974

Orgin: Bollington, Cheshire, England

Proffesor of physics at University of Liverpool in 1935

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Education Chadwick attended Manchester high

school, he graduated from the Honours School of Physics in 1911. He spent two years under proffesor Rutherford in the Physical Laboratory in Manchester were he worked on radioactivity problems and gained his M.sc degree in 1913.

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Discoveries

He discovered the neutron

He also discovered the nucleus of the atom

Theories DisprovenJames Chadwicks’ theory that electrons rotate around the

nucleus in defintie pathes was disproven Electrons actually form a cloud around the nucleus

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Ernest Rutherford

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…Rutherford born on August 30, 1871and he died on October 19, 1937 in Brightwater, New Zealand.

In what period of time did he live and what is his country of origin?

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When did he conduct his experiment?

He conducted his experiment on………

1911by Hans Geiger and Ernest Marsden at the suggestion of Ernest Rutherford. Geiger and Marsden expected to find that most of the alpha particles travel to straight trough the foil with little deviation, with a remainder being deviated by a percent or two.

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What was he trying to prove w/ his experiment?

 Rutherford proving about the existence of  …….. Neutrons. It was named by James Chadwick.

Which could somehow compensate for the repelling effect of the positive charges of protons by causing an attractive “nuclear force” and thus keep the nuclei from flying apart from repulsion between protons.

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Summarize his experiment (what he did and what he discovered)

Gold Foil Experiment

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The gold foil experiment consisted of a series of tests in which positively charged alpha particles (helium nuclei) were fired at a very thin sheet of gold foil. If Thomson's Plum Pudding model was to be accurate, the big alpha particles should have passed through the gold foil with only a few minor deflections. This is because the alpha particles are heavy and the charge in the "plum pudding model" is widely spread.

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In detail, a beam of alpha particles, generated by the radioactive decay of radon, was directed normally onto a sheet of very thin gold foil in an evacuated chamber. A zinc sulfide screen at the focus of a microscope was used as a detector; the screen and microscope could be swivelled around the foil to observe particles deflected at any given angle. Under the prevailing plum pudding model, the alpha particles should all have been deflected by, at most, a few degrees; measuring the pattern of scattered particles was expected to provide information about the distribution of charge within the atom.

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Why was he surprised by his experimental results?

Bec. On his experiments, many of the alpha particles did pass through as expected, many others were deflected at small angles while others were reflected back to the alpha source.

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How did his results fit w/ Thomson’s view of the atom?

Since none of Thomson's negative "corpuscles" (i.e. electrons) contained enough charge or mass to deflect alphas strongly, nor did the diffuse positive "pudding" or cloudlike positive charge, in which the electrons were embedded in the plum pudding model. Instead, Rutherford suggested that a large amount of the atom's charge and mass is instead concentrated into a very physically small (as compared with the size of the atom) region, giving it a very high electric field. Outside of this "central charge" (later termed the nucleus), he proposed that the atom was mostly empty space. 

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a number of tiny electrons circled the nucleus like the particles then hypothesized to make up the ring around Saturn.  By implication, Rutherford's concentration of most of the atom's mass into a very small core, made some type of planetary model an even more likely metaphor than before, as such a core would contain most of the atom's mass, in an analogy to the Sun containing most of the solar system's mass.

Describe his model of the atom

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WERE His beliefs accepted by the society at that time?

His beliefs were accepted until one scientist made an experiment regarding Rutherford’s experiment. He is Niels Bohr.

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NIELS BOHR … .

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Born On : 7th October 1885

Death : 18th November 1962

Nationality : Danish

Field : Physics

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In 1912 he married his wife, Margrethe Norlund. He had six childeren, two of them died. One of their sons, Aage Bohr grew up to be an important physicist who recieved the Nobel Prize in 1975.

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In 1912 he met and later joined ErnestRutherford at Manchester University.In 1922, Bohr was awarded the NobelPrize in physics.Bohr had adapted Rutherford's nuclearstructure .

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Bohr model of the atom(part I)1.The electrons can only travel in certainorbits.2.The electrons of an atom revolve aroundthe nucleus in orbits.

Bohr introduced the ideathat an electron could dropfrom a higher-energy orbitto a lower one, in theprocess emitting aphoton(light quantum) ofdiscrete energy.

Bohr model of the atom(part II)

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Thank You =‘)